Toolholders

ABSTRACT

This toolholder has a specially designed collet in which the different shaped generally hexagonal, shanks of two different tools, like an Allen wrench and a Bristol wrench, for example, can be mounted interchangeably for endwise adjustability.

United States Patent [56] Relerences Cited UNITED STATES PATENTS 1,369,632 2/1921 Diel 279/49 2,270,420 1/1942 Dinhofer v 279/46 UX 2,885.210 5/1959 Sima 279/49 3,096,989 7/1963 Fallon 279/48 3,4] L796 I 1/1968 Decker 279/46 Primary Examinr-Andrew R. luhasz Assistant Examiner Donald D. Evenson Attorney-Andrew F. Wintercom ABSTRACT: This toolholder has a specially designed collet in which the different shaped generally hexagonal, shanks of two diflerent tools, like an Allen wrench and a Bristol wrench, for example, can be mounted interchangeably for endwise adjustability PATENTEU JUL27 l97i FIG. I

INVENTOR TOOLIIOLDERS This invention relates broadly to tool holders or chucks but, more particularly. one specially designed and constructed to be used as a toolholder interchangeably with an Allen wrench bit and a Bristol wrench bit, holding either of these bits with substantially equal firmness, when tightened, and permitting endwise adjustment ofeither bit with substantially equal facility when loosened.

The salient feature of the toolholder of my invention is in slotting the outer end of the collet to define jaws of keystone shape in cross section and of the required width that fit snugly in the longitudinal grooves of a Bristol wrench bit to provide a sure nonslip drive connection for the holder and one which permits easy longitudinal sliding adjustment of the bit when the holder is loosened, this same holder when an Allen wrench bit of the same size is to be used holding it in the same satisfactory manner by virtue of the slots being of substantially the same width as the radially inner width dimension of the jaws, so that the six corners of the hex of the Allen wrench bit find engagement at l2 points in the slots between the jaws while the six jaws engage the six flats of the hex at their midpoints for solid holding engagement.

The invention is illustrated in the accompanying drawing, wherein:

FIG. I is a perspective of the toolholder of my invention, showing it with an Allen wrench bit inserted;

FIG, 2 is a longitudinal section on line 2-2 of FIG. 1;

FIG. 3 is a cross section on line 34! of FIG. 2 on an enlarged scale;

FIG. 4 is an enlarged side elevational detail of the slotted and tapered end of the collet;

FIG. S is a perspective similar to FIG. I but showing the same toolholder, showing it with a Bristol wrench bit inserted;

FIG. 6 is a longitudinal section of FIG. 5, and

FIG. 7 is an enlarged cross section on line 77 of FIG. 6, the toolholder parts being shown as of the same size as in FIG. 3 for best illustration of the interchangeable use with either an Allen or a Bristol wrench bit of the same size.

The same reference numerals are applied to corresponding parts throughout these views.

Referring to the drawing, Allen wrench bits like the one shown at A in FIGS. 1-3 are of hexagonal cross section, with six flat faces 8 defining six corner portions 9. Bristol wrench bits, like the one shown at B are generally circular in cross section and have six evenly spaced longitudinally extending radial ribs 10 defined between six longitudinally extending grooves ll. Comparing these two different styles of tool hits, it is easily understandable that, prior to this invention, each required its own style of toolholder. So far as I am aware, the toolholder 12 of my invention is the first usable interchangeably with these two different styles of bits to hold them with substantially equal firmness when tightened and permitting endwise adjustment of either bit with substantially equal facility when loosened.

The toolholder I2 comprises a specially designed collet sleeve 13 carried on an externally threaded head 14 and square tubular drive shank l5 and fitting inside a draw-sleeve I6 that has an annularly flanged inner end 17 fitting inside a knurled draw-nut 18 having an annular flange I9 abutting the flange 17 to cause contraction of the collet sleeve 13 on whichever one of the bits A or B is entered in the collet, the contraction being clue to the outside taper 20 on the outer end of the collet sleeve fitting wedgingly in the complementary taper 21 in the restricted outer end of the bore of draw-sleeve 16 where the annular shoulder or land 22 is defined. There is also a similar restriction in the bore of the collet 13 near its outer end defining another annular shoulder or land 23. The six clamping jaws 24 for gripping tool bits A and B are of keystone-shaped cross section, as seen in FIGS. 3 and 7, and are provided by the special slotting of the outer end portion of the collet radially, as at 25, so that (I the slots are of substantially equal width with the radially inner faces on the jaw: 24 and (2) opposite sides of each slot are parallel to one another. By virtue of this slotting of collet 13, as at 25, at the six equally circumferentially spaced points:

A. the keystone-shaped jaws 24 fit snugly in the grooves II between the six ribs 10 on a Bristol tool bit B, gripping thebit at 18 points, namely, at the bottom of each of the six grooves II and at opposite sides of each of the six ribs I0, to grip the bit firmly and transmit drive thereto, and

B. there is room enough in each of the slots 25 between the jaws 24 for the six corners 9 of the hex section of Allen tool bit A for transmitting drive thereto on opposite sides of each comer while the engagement of the jaws on the six flat faces 8 hold the bit firmly.

The slots 25 extend sufficiently beyond the inner ends of jaws 24, as seen in FIGS. 2, 4, and 6 to enable flexing these jaws radially inwardly relative to the rest of the collet 13 for substantially full length engagement of the jaws with either of the tool bits A and B to make for maximum rigidity of the bit in the holder.

In operation, with either tool bit in the holder 12, one can easily adjust the tool bit longitudinally after first loosening the nut 18, and, if necessary, a draft pin can be entered in the bore of the tool holder through the hollow drive shank Is to adjust a tool bit to the desired extent or remove it from the holder. The annular clearance at 23 inside the collet I3 provides working clearance for the longitudinal ribs II on the Bristol bit B, as seen in FIGS. 6 and 7 as they extend beyond the radius of the inner faces of the jaws 24 of the collet, whereas in dealing with an Allen bit A as in FIGS. 2 and 3, these jaws 24 engage the flat faces 8 as seen in FIGS. 2 and 3. t

In conclusion, while I have shown two different wrenches in connection with a single toolholder fitting their different shanks and permitting endwise adjustment thereof relative to the holder, it should be clear that the invention is not limited to use with wrenches, as, of course, it is immaterial whether the shanks entered in the collet are on wrenches or other tools,

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

lclaim:

1. In a toolholder chuck for use interchangeably with sixsplined Bristol-type bits and hexagonal flat-faced Allen-type bits, in collet sleeve having a bore with a reduced end portion, said sleeve having this end portion tapered on the outside toward the outer end, said sleeve having six equally circumferentially spaced slots of uniform width from end to end cut radially therein in said end portion extending longitudinally thereof to define six jaws longitudinally of and between said slots, the jaws being of keystone cross section transversely thereof and the slots having parallel sides and being of substantially equal width to the radially inner width dimension of said jaws, and a draw sleeve having a bore in which saidcollet sleeve is received, said bore having one end portion tapered to match the outside taper on the collet end portion, said drawsleeve being tightenable relative to said collet sleeve.

2. A toolholder chuck as set forth in claim 1 wherein the slots in said collet sleeve are extended beyond the inner end said jaws.

3. A toolholder chuck as set forth in claim I wherein the draw-sleeve has the bore therein of large radius in relation to the collet sleeve received therein and reduced at the end portion that is tapered to match the outside taper on the collet.

4. In a toolholder for adjustably mounting a hexagonal Allen wrench bit, having the usual six fiat faces, a collet sleeve having a bore with a reduced end portion, said sleeve having this end portion tapered on the outside toward the outer end, said sleeve having six equally circumferentially spaced slots of uniform width from end to end cut radially therein in said end portion extending longitudinally thereof to define six jaws longitudinally of and between said slots, the jaws being of the six ribs defined between said grooves are received in the slots of the collet sleeve, said six slots cut radially in said sleeve being all of one width substantially equal to the radially inner width dimension ol'said jaws. 

1. In a toolholder chuck for use interchangeably with sixsplined Bristol-type bits and hexagonal flat-faced Allen-type bits, a collet sleeve having a bore with a reduced end portion, said sleeve having this end portion tapered on the outside toward the outer end, said sleeve having six equally circumferentially spaced slots of uniform width from end to end cut radially therein in said end portion extending longitudinally thereof to define six jaws longitudinally of and between said slots, the jaws being of keystone cross section transversely thereof and the slots having parallel sides and being of substantially equal width to the radially inner width dimension of said jaws, and a draw sleeve having a bore in which said collet sleeve is received, said bore having one end portion tapered to match the outside taper on the collet end portion, said draw-sleeve being tightenable relative to said collet sleeve.
 2. A toolholder chuck as set forth in claim 1 wherein the slots in said collet sleeve are extended beyond the inner end said jaws.
 3. A toolholder chuck as set forth in claim 1 wherein the draw-sleeve has the bore therein of large radius in relation to the collet sleeve received therein and reduced at the end portion that is tapered to match the outside taper on the collet.
 4. In a toolholder for adjustably mounting a hexagonal Allen wrench bit, having the usual six flat faces, a collet sleeve having a bore with a reduced end portion, said sleeve having this end portion tapered on the outside toward the outer end, said sleeve having six equally circumferentially spaced slots of uniform width from end to end cut radially therein in said end portion extending longitudinally thereof to define six jaws longitudinally of and between said slots, the jaws being of keystone cross section transversely thereof, and a draw-sleeve operable endwise relative to the outside of said collet sleeve, the hexagonal Allen wrench bit being adapted to have its six flat faces clampingly engaged by the radially inside faces of the six jaws of said collet, the six jaws also being of a width to fit snugly in the six grooves of a Bristol-type wrench bit when the six ribs defined between said grooves are received in the slots of the collet sleeve, said six slots cut radially in said sleeve being all of one width substantially equal to the radially inner width dimension of said jaws. 